


contretemps

by Tsume_Yuki



Category: Harry Potter - J. K. Rowling, The Rigel Black Chronicles - Fandom
Genre: Dimension Travel, F/M, Female Harry Potter, Gen, I don't know, Potions Accident, i just think they're neat, pre-ship maybe?, shippy if you want it to be
Language: English
Status: Completed
Published: 2020-11-15
Updated: 2020-11-15
Packaged: 2021-03-10 02:32:55
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,812
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27576551
Author URL: https://archiveofourown.org/users/Tsume_Yuki/pseuds/Tsume_Yuki
Summary: “Wonder what’ll happen with him,” Ron muses, his stomach growling and signalling their next destination is to be the Great Hall.“Snape’ll probably cut him up for potion parts,” Harry quips and he’s not even surprised to find he’s only half joking.As it turns out, the stranger is not used for potion parts.Dumbledore announces, after a thorough investigation including the use of truth serum, that they will be housing another person from an alternate universe, Harry would have thought the truth serum was too much, a little too cautious, until he heard the name.Lestrange.
Relationships: Harriet Potter | Rigel Black & Caelum Lestrange
Comments: 29
Kudos: 301
Collections: Rigel Black Exchange Round 2





	contretemps

**Author's Note:**

  * For [Tamari](https://archiveofourown.org/users/Tamari/gifts).



> happy birthday babe (sorry about the rushed fic)

Harry had been certain potions classes could not get any worse. True, it had become his second least favourite (a miracle in itself but, given the Toad, he’d had no choice but to drop DADA to the enviable place of his least favourite lesson) yet, that was had nothing to do with any actual improvements in the potions class itself. In fact, Snape seemed determined to go out of his way to make everything worse than it actually was, as if sensing he’d lost his position as the most hated teacher among the students of Hogwarts and was determined to regain his title.

Overall, it made for a terrible hour stuck in the dungeons and, as if the weight of knowing he needs to do well in potions in order to get the OWL level needed for becoming an Auror wasn’t bad enough of a stressor, there’s the sudden tear in the air that has Harry leaping out of his seat in shock. He’s not the only one; everyone scrambles back and away from the sudden cloud of energy, the whole thing a snapping, vicious purple that has Snape drawing his wand and snarling at the sudden disturbance to his class. Only, it’s right by the blackboard, so cannot possibly have come from any of their potions. Neville is bad, but even he has only added two ingredients so far; it’s impossible that this thing is any of their fault.

Then, a body drops through the cloud to the floor with a soft 'thump'. That just about tops Harry off in truth.

He shares a glance with Hermione, hoping against hope that she has some idea of what is happening. A Death Eater maybe? It’s certainly not Voldemort; there’s a head of black hair and, though it’s as carefully styled as the Diary’s was, there’s something far more modern about it. Besides, Harry destroyed the diary; it’s not possible.

Snape stands before them all, wand raised and angled at the body that’s lying on the floor and doing nothing much other than groaning to itself.

“What the hell?” Ron hisses, quickly finding his lips silenced with a spell from Snape, who doesn’t even look at them, still too busy staring hard at the intruder.

Then, the other speaks, a soft “fuck,” that has Hermione drawing a hissing breath through her teeth.

Slowly, the person dropped into their class sits up, pressing a hand to his bleeding temple and Harry gets the chance to see a flash of blue eyes before Snape is hustling them out of the lab.

With lessons dismissed, they swarm out into the halls and, for the first time in forever, no one is in a rush to get out of the dungeons. They all linger as long as physically possible and Harry is no different. Because-

“You can’t apparate into Hogwarts,” Hermione declares, the voice of reason over Ron’s suggestion, her brown eyes narrowed as she assesses them all. “And besides, that cloud of energy is certainly not how apparition works. I’ve read about it in preparation for our licences.”

“Blimey, Hermione. Our licenses don’t matter until next year.”

Harry hums, thinning his lips as Ron and Hermione descend into the usual arguments.

The face wasn’t Tom Riddle’s, but there’d been something both familiar and unfamiliar about it, like he’d seen the guy’s dad or something before. Only, he’s pretty sure he’d be able to remember them. He hopes. Lavender and Parvati both flutter by, sharing a breathy giggle as they go, muttering on how pretty the intruder had been. And, yeah, Harry could kinda see that in the same way he’d seen the pictures of a young Sirius and known he was good-looking too.

“Wonder what’ll happen with him,” Ron muses, his stomach growling and signalling their next destination is to be the Great Hall.

“Snape’ll probably cut him up for potion parts,” Harry quips and he’s not even surprised to find he’s only half joking.

As it turns out, the stranger is not used for potion parts.

Dumbledore announces, after a thorough investigation including the use of truth serum, that they will be housing another person from an alternate universe, Harry would have thought the truth serum was too much, a little too cautious, until he heard the name.

 _Lestrange._ Caelum Lestrange, a visitor from another universe who’d had a potions accident and was already back in the potions lab trying to figure out how to return.

“It’s suspicious is what it is,” Ron growls under his breath around a mouthful of chicken, his eyes narrowed as he looks across the room to the Slytherin table. Harry follows his gaze to himself looking at Malfoy. His swift introduction to the Black family tree over summer comes in handy here; Draco’s mother’s sister is Bellatrix Lestrange, isn’t she? Though the announcement of Caelum Lestrange’s presence hadn’t come with a family tree, it isn’t hard to see the shared features now. The high cheekbones, slight curls; both had been things Harry had seen in the paper the day after the Azkaban breakout. Admitted, Bellatrix Lestrange had looked infinitely more weathered, but the features are the same.

Which means, given that connection, Harry needs to investigate.

It almost kills him, waiting for Hermione to go get changed following dinner and for Ron to stumble off and do the same thing; it’s the only opportunity he has to slip free of their heavy gaze to go and sneak down himself.

The hallways of Hogwarts are near empty by now with curfew looming, leaving Harry’s steps to quietly echo his every move towards the dungeons. He trusts Dumbledore of course, knows that the Headmaster wouldn’t put them in danger like this by allowing a potential unknown to stay within the castle. This is the one place Voldemort could never get to because Dumbledore resides here. Snape, a damn Death Eater for all that he’s a spy, is only here because Dumbledore allows him to be.

But that doesn’t mean Dumbledore knows all; Harry only needs to look to the Diary to know that for certain. So, he’ll probably get more detentions than he’ll know what to do with if he gets caught here (and his hand aches with the thought of the Toad catching him) but he just cannot leave it alone. Not when there’s Bellatrix Lestrange running around out there and then, suddenly, a Lestrange from an alternate universe decides now’s the time to drop in. After all, Voldemort knows darker magic than anyone else; maybe he’s done something to Caelum Lestrange to alter his memories until it’s time, or until there’s a signal or something?

~~Maybe it’s something to do with the corridor he keeps seeing in his dreams…~~

Stopping outside of the potions lab that Snape usually haunts, Harry holds his breath as he edges closer to the door, the light refracting awkwardly around the invisibility cloak as he shifts. Once he’s finished moving, the world around his settles and he can see inside the open door.

Caelum Lestrange is hunched over a workbench, two cauldrons brewing simultaneously and a look of deep concentration on his face. Beside him, Snape has a look of naked shock on his face, watching the cauldrons slowly turn green despite the fact neither of them are adding any ingredients or stirring anything.

“That’s not possible,” Snape barks out, looking deeply disturbed by whatever it is Lestrange is doing and Harry slowly edges closer, entering the classroom to get a better look. Because Snape is supposedly a great potions master (and an asset to the Order of the Phoenix according to Dumbledore, but Harry’s not too sure about that) so if he doesn’t recognise what Lestrange is doing, that’s probably a bad sign.

“It’s definitely possible,” the boy snaps back, a look of contempt overtaking his fine features but he doesn’t glance away from the potions he’s keeping a steady eye on. “I told you, it’s a highly advanced technique that was only created in our world two years ago. There are only three potioneers capable of it and I just so happen to be one of them.” Merlin, what a pompous asshole. He’s definitely related to Malfoy, though Lestrange may just have the talent to back it up if the way Snape is reacting is any indication. That’s… worrying. However, it’s also a clear indicant that he is from another world which is… is good. There’s less chance of him working for Voldemort… unless he’s working for the Voldemort of that dimension?

There’s too many questions adding up for Harry and he doesn’t like it, doesn’t like the potential problems Lestrange can cause. Even if, at this moment, the Toad is the biggest threat.

Harry settles in for a long wait, resigning himself to the fact he needs to gather more information. A lot of it goes over his head, would probably have gone over even Hermione’s head. Snape and Lestrange talk potions like they breathe; as if it’s all they do and it’s their natural state of being. He’s just a bit freaked to see Snape actually relaxing into the conversation, even if he seems astounded that whatever Lestrange had been doing has actually worked. Something about shape imbuing but that means squat to Harry. All he’s managed to gather is that it shouldn’t be possible according to Snape, only it clearly is, and that Lestrange is a smug fuck over being able to do it.

Admittedly, if Harry could do something only two other people in the world could do (and if it’d been a product of his own hard work and not a streak of freak luck like the damn scar on his forehead) he’d probably be a little smug about it too.

Regardless, he sits there for what is at least an hour as Lestrange talks through the method, doing his best to memorise it so that Hermione can have a go at recreating it later. Only, once Lestrange starts talking about wandless magic, that’s where Snape cuts him off.

“Don’t be anserine, wandless magic like that is beyond almost everyone.”

“Don’t be obstinate,” Lestrange counters with another pompous sniff, holding out his hand with the palm facing the ceiling. A moment later, a miniature cyclone begins to form in the cradle of his hand, whirling around with a smooth burst of power that leaves Harry’s mouth dry. Because- what? What the actual fuck? Wandless magic isn’t supposed to be possible, is it? Dumbledore can extinguish candles, Voldemort could do small shit as a child, but… controlled like that?

Snape is goggling. Harry’s glad he’s not the only one who’s absolutely astounded. Only the light sheen of sweat on Lestrange’s brow shows that the display of magic took some effort for him. But this- this is exactly the kind of thing he needs to sneak out of the common room for, the exact kind of thing he needs to know because- fuck. Wandless magic to summon up a mini-cyclone? Just what is Lestrange capable of when using a wand? He cannot be allowed to go to Voldemort here, Voldemort cannot find out about Lestrange because he’ll try to recruit him and then-

Then there’s suddenly another purple cloud of magic. Only, it’s a hell of a lot closer to Harry than he feels comfortable with.

He hears Snape curse, hears Lestrange’s sharp intake on breath and then there’s a body falling directly onto him.

It knocks the breath out of Harry, knocks the words from his lungs and his feet out from under him. Worse, it knocks the invisibility cloak so that half of his body is suddenly uncovered, half tangled in with the other person who has appeared out of nowhere and is rolling off him.

There’s a moment of stunned silence as both Snape and Lestrange take in the half visible bodies, as Harry takes in the sheer misfortunate that has literally fallen on top of his head, and as the extra body comes to terms with their sudden change in position.

“Potter!” the two potioneers shout and they could not be more different in the tones they use; enraged fury and surprised delight. Only Snape continues, following with a “fifty points from Gryffindor!”

“Oh. Caelum. That’s good; I wasn’t expecting it to work.” The voice is female and the body rolls off him, leaving Harry both with the ability to breathe and no excuse to not remove his invisibility cloak now that he has been caught. Well, that’s not entirely true; he’d have a slightly higher chance of bolting away from Snape with it, but the man has already seen him. Punishment is inevitable; staying and taking his lumps now would probably be for the best. That, and he might actually find out what the hell is going on if he does.

Pulling the fabric from his head, Harry turns and startles at the very bright, very green eyes that peer back at him with something academically curious in them. It’s not quite the way that Hermione looks at a textbook (that’s more like a challenge to be beaten into submission and forcibly conquered). No, it’s more like… more like how Neville looks at a plant. Something he finds fascinating and is almost excited to see how it works, what it needs to live. It’s not exactly a comforting sensation to be on the end of such a look.

“Get up, brat. Even you shouldn’t lower yourself to sprawling across the floor.”

“Well, it’s certainly not the comfortably charmed floor of your ivory tower,” the girl quips back, rising to her feet and brushing the dirt from her robes with two swift sweeps of her hands, the bag at her hip shifting only ever so slightly with the motion.

“Don’t be ridiculous, Potter. Dartmoor isn’t made of ivory.”

“It wouldn’t fit your dark aesthetic,” the girl responds agreeably, turning to look at Harry again and Harry stares in return. Because, she’d answered to Potter. Lestrange has called her Potter twice and she’s answered to it both times; neither time has the older boy been talking to Harry.

Does he have a twin in this alternate dimension? Why is she hanging around Lestrange who may very well be the son of Bellatrix Lestrange, Malfoy’s cousin?

“Lestrange,” Snape growls out, eyeing the girl that answers to Potter warily, his wand out again. Harry might not like Snape, might be highly suspicious of Lestrange, but he sure as hell isn’t going to draw more attention to himself right now. Not when he’s just lost fifty house points and Snape's rage doesn’t even seem to be tempered by it yet.

Greasy bat.

“Who is this?”

“Harriet Potter,” Lestrange drawls, eyeing the newly arrived Harriet Potter with a wry smirk, eyebrows rising up in a silent question and the girl just lifts her own in return, as if totally unbothered by the wizard now introducing her. “She’s the creator of the shape imbuing technique.”

“Aww, have you been singing me praises, Caelum?” She does... _something_ with her face. Harry isn’t too sure what it is, but he can see the fact it’s aimed at Lestrange and that it clearly has an effect, given the flushing of his pale cheeks and the startled parting of his lips.

“You’ve come up with a potioneering trick that is difficult to reproduce, brat. Hardly singing you praises.”

“Which is why you wrote asking to base your masters on it?”

“Shut up, Potter. It has some worthwhile applications that could advance a handful of fields. Don’t get big headed.”

“Yes, I suppose your own ego does need some breathing room,” Harriet Potter states pleasantly, looking around the potions lab before offering Snape a respectful nod. “Professor Snape. I’m afraid the potions accident that brought us here will be keeping us here for the full cycle of the moon-”

“Because of the moondew,” Lestrange finishes with a furious hiss of realisation, raking a hand through his hair before he flicks the girl across the nose, ignoring her surprised blink. “That ingredient was your idea.”

“It was supposed to counteract the potential of splinching,” she states pragmatically, though seemingly perturbed by the sudden, almost friendly reprimand that had been Lestrange's gentle flick. As friendly as an icy bastard like Lestrange could be, that is.

Snape, however, still seems to be stuck. He’s staring at the girl, much the same as Harry himself is. Only after an uncomfortably long silence (in which both Caelum Lestrange and Harriet Potter share a look) does he appear to find his voice.

“You’re the Potter of an alternate dimension.”

“Yep.”

“And you created the potions technique- the shape imbuing?”

“I did. I’d be happy to go over the technicalities of it during our stay.”

Their stay. An alternate Harry Potter who is both a girl and apparently friends with Lestrange.

Holy fuck.

**Author's Note:**

> Maybe someday I'll add more of Harry & Caelum's adventures in Canon but, for now, we're done.


End file.
